Piezoelectric crystal holder



June 17, 1941.

J. RICHTER 2,246,384 PIEZOELECTRIC CRYSTAL HOLDER Filed Feb. 10, 1940 JW m l INVENTOR.

ATTORNEY.

Patented June 17, 1941 PIEZOELECTRIC CRYSTAL HOLDER Johann Richter, Berlin, Germany, assignor to Telefunken Gesellschaft fiir Drahtlose Telegraphie m. b. H., Berlin, Germany,

tion of Germany a corpora- Application February 10, 1940, Serial No. 318,381 In Germany November 30, 1938 4 Claims.

This invention relates to circuits utilizing glow quartz or sound quartz and aims principally at expanding the narrowly confined properties demanded of such quartz crystals in order that they can be utilized efiectively. When using glow quartz and sound quartz in wireless apparatus, it has hitherto been necessary that the ignition potential or sound potential of the quartz crystals had to be confined within very narrow limits since the potential was individually dependent on the quartz crystal. This necessitated an individual selection of the quartz crystal to suit the possibility of use in certain circuits and this involved considerable examinations and a great many pieces had to be Wasted. The invention relates to a circuit and a crystal holder which avoids the said drawbacks.

In accordance with the invention, a circuit for use of glow quartz or sound quartz is characterized in that the quartz is placed in series to a resistance of a few thousand ohms. As a result of this, the control range of the potential in which the quartz glows or sounds properly is essentially wider and there is the further advantage that the setting in of the glowing or sounding becomes much softer. Owing to the wider potential range available, such rigid requirements as were hitherto demanded as regards the quartz crystal, are no longer necessary, so that the number of wasted quartz pieces is reduced. Another advantage resides in the fact that contrary to the hitherto necessary use of the crystal in one and the same apparatus, the quartz can with few exceptions, be utilized in all apparatus of the same type and can thus be interchanged. On account of the use of the series resistance, it may be at the most necessary to use a somewhat higher potential than is the case in the known circuits having no series resistance, but the power to be provided is higher to an unessenti-al extent only since the glow currents of the quartz crystals are in the order of about ampere.

It is of particular advantage to combine the series resistance with the glow quartz or sound quartz so as to form a single unit whereby the resistance is arranged in the base of the bulb or in the glass bulb. An example of such a unit is shown in the figure in which a glow quartz Q is combined with a resistance W placed in series thereto. The term sound quartz as utilized in the above description is meant to denote a resonator quartz crystal in circuit with a variable oscillator circuit. If the tuning of the oscillator is varied, a brief sound appears at resonance in a loud-speaker connected to the circuit, which sound is due to the initial oscillation performance of the quartz crystal. Such sound circuits are therefore well suited for measuring the frequency.

What is claimed is:

1. A piezo-electri-c crystal holder comprising a crystal element, a glass envelope for enclosing said crystal element, a base member supporting said glass envelope and said crystal element, and a resistance located within said base and connected in series with said crystal element.

2. A piezo-electric crystal holder comprising a crystal element, a glass envelope for enclosing said crystal element, a base member supporting said glass envelope and said crystal element, said base member having a plurality of terminal plugs to permit the holder to be interchanged with other apparatus, and a resistance located within said base and connected in series with said crystal element.

3. A piezo-electric crystal holder comprising a. crystal element, a glass envelope for enclosing said crystal element, a base member supporting said glass envelope and said crystal element, and a resistance of a few thousand ohms located within said base and connected in series with said crystal element.

4. A piezo-electric crystal holder comprising a crystal element, a glass envelope for enclosing said crystal element, a base member supporting said glass envelope and said crystal element, said base member having a plurality of terminal plugs to permit the holder to be interchanged with other apparatus, and a resistance located closely adjacent to and connected in series with said crystal element and said terminal plugs.

J OHANN RICHTER. 

